Feedeeick gutzkow



UNITED STATES PATENT OFFICE FREDERICK GUTZKOW, OF SAN FRANCISCO,CALIFORNIA.

MANUFACTURE OF CARBONATE OF MAGNESIA.

SPECIFICATION forming part of Letters Patent No. 235,231, dated December7, 1880. Application filed April 1, 1880. (Specimens) To all whom it mayconcern Be it known that I, FREDERICK GUrzKow, of the city and county ofSan Francisco, and State of California, have invented an ImprovedProcess for Manufacturing Carbonate of Magnesia; and I do hereby declarethat the following is a full, clear, and exact description thereof. 7

My invention relates to an improved process or method of preparing thebasic carbonate of magnesium, commonly called magnesia alba, fromliquids containing chloride of magnesium, and in particular from themotherliquor of marine salt-works, called bittern.

To do this I employ three successive steps or operations, using no othermaterial but lime, Water, and carbonic acid, and requiring no otherapparatus but such as are commonly known.

In the first operationI mix the bittern with milk of lime in suchproportion that there remains an excess of magnesia in solution, whenthe lime will dissolve as chloride of calcium, precipitating itsequivalent weight of insoluble hydrate of magnesium.

To the second step or operation I remove the soluble salts of calciumand of other bases by washing the hydrate of magnesium with water,either by decantation or filtration.

To the third step or operation I run the pulp of hydrate of magnesiuminto a vessel, which may be constructed in the manner of the wet limepurifiers in use in gas-works,

heat it by steam or otherwise to 120 Fahrenheit, and force through thepulp the gaseous products from the combustion of coke or other gascontaining carbonic acid. Under the influence of the elevatedtemperature the hydrate of magnesium will combine with the carbonic acidinto a carbonate which has the volume and lightness demanded of thecommercial article, and the operation is finished when a dried sample ofthe pulp shows those qualities.

Instead of the temperature of 120 Fahrenheit, which I find by experiencethe most advantageous, a higher temperature may be employed. The pulp ofthe basic carbonate of magnesia is then drained and dried in the usualmanner.

Having thus described my invention, what I claim, and desire to secureby Letters Pat ent, is-

In the manufacture of magnesium carbonate, the described process ofobtaining it in a light and flocculent form, which consists in heatingthe pulp of magnesium hydrate, and forcing carbonic-acid gas through thepulp while it is in a heated state, substantially as specified.

In witness whereof I have hereunto set my hand.

FREDERICK GUTZKOW. Witnesses:

WM. F. CLARK, EDWARD E. OsBORN.

